It is well known from the art, that the most important pathogenic fungi of cereals (e.g. wheat, barley) are as follows:
smut diseases, such as bunt smut of wheat (Tilletia foetida), loose smut of barley (Ustilago nuda) and the fusarium species (Fusarium spp.) which infect the plant in embryomic stage partly in the soil, partly internally in the seed; PA1 powdery mildew species (e.g. Erypsiphe graminis) which attack the plant in several stages of growth; PA1 cereal fusarium fungi (Fusarium graminearum) and rusts (e.g. Puccinia glumarum) which attack the corn after earing.
The infections of the plant seed are treated by seed-dressing, while the later fungal attacks are treated with foliar spray application of different kinds of fungicides.
So far mercury containing compounds have been used for seed-dressing of corn. However, these compounds have several disadvantages. The health-detrimental and accumulating effect of mercury containing compounds is well known and the compounds do not protect the seeds from internal infections.
The activity of benzimidazol-2-ylmethylcarbamate (BMC, trade name: carbendazime) against phytopathogenic fungi was first described by H. Hampel and F. Locher [Proc. Br. Insectic. Fungic. Conf. 7th, (1973) pp 127, 301], and the utility of this compound as an antifungal foliar spray was referred to in U.S. Pat. No. 3,657,443.
Powel reported on the protective fungicidal effect of the copper complex of 8-oxyquinoline the first time in the second half of the 1940's [Phytopathology, 36, p. 573, (1946)].
In Hungarian patent specification No. 171,736 the very favorable fungicidal effect of the mixed liganded (8-oxyquinolinate)-(dimethyl dithiocarbamate) metal complexes is described. These metal complexes are always more effective--especially if the central atom is zinc, manganese, copper, magnesium, iron, cadmium etc.--than the metal complexes of either 8-oxyquinolinate or dimethyl dithiocarbamate comprising the same ligand. It is further reported, that a mixture containing 1 part by weight of zinc complex and 1 part by weight of manganese complex is preferred.
According to Polish patent specification No. 104,686 a mixture of the copper complex of (8-oxyquinolinate)-(dimethyl dithiocarbamate) and carbendazime of a weight ratio 1:1 possesses synergistic effect against the fungi Rhizoctonia solani, Phome betae and Helminthosporium gramineum.